When adding Ribbon Custom Action to Site Assets library using Visual Studio, the list template 851 is selected incorrectly, it simply does not exist. The list template for Site Assets is 101 and to add custom action to it we need to use List Instance.

If you receive this error message: “Import-PSSession : Files cannot be loaded because the running of scripts is disabled on this system. Please provide a valid certificate with which to sign the files.”
…then run this cmd-let prior to the one above: Set-ExecutionPolicy Unrestricted

If you need to display a mini calendar on your page, there’s no need to create a new webpart, simply add custom styles to the normal calendar view. It looks great and even functions exactly like the normal calendar

It’s a very common SharePoint scenario to use lookup fields pointing to the lists on other sites. However, SharePoint doesn’t always like it when we use such lookups. One such example is when we try to read or update values in those fields using a workflow – we get “The field ‘Lookup’ is not supported in query. The lookup list is in another web” error. Fortunately, now SharePoint Designer has HTTP Web Service action that we can use as a workaround.